SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '65472d9bd267c7403dc2fc087791c6736952c80d488f2059850e0b0a6665fde7' 
  AND token = 'dMBHYPBRDGuRbvIZ1JEphYsz3CDbV2ZCZrgU7RRRNLU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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