SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '707e4674d4c83f6f2c452a585b0072c2be12da722f1b241c487437ad50f0aa27' 
  AND token = '3oypuBsCnojMmTI+iBRRNl0Ha2U4Bw3GnIL7SZNZvXA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}