SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7415564ebb6c231ab0a2e57df245aa1f3f84a0a41c1297d4795e082852cade32' 
  AND token = 'KYpBaXZRqS9ityUlaqkE7GMsINZMEoiVlDEfq0ULFqE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}