SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7ea1cf475a51c958137c4389e034456981bfc48326fbda50ae797fb981e9b590' 
  AND token = 'iPzHxhnU2Qg0VWwSO9drwHfpDXcMdrRGEewgOtUtXGk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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