SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a5316dbef1272cd8fdec3220ab9d80a4ecb5b069953b177043c506a0d50c4e7a' 
  AND token = 'T8wNExMEMivVI5JmZX1AsK3G2kAihGaYnl/47zHVVjY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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