SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '114d5ac0d3e62d6d908c7328747f770883dea1d2242b265337464e4e9090e499' 
  AND token = 'ZkmsGccrQzstvyoByodzCGgiUGwMPiZme2PjFo40wHs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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