SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '077b9c8914550474edf1e65a95144cd18d8858314f3618d5cd754e31db0b92c5' 
  AND token = 'KpnOmHuY7bw0V7EHtE3aLTo0+PKP99JlaFCJzjh3VG8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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