SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f223aad8616294f6376fec496dcd64ea243a48fe831a264b2918826df61cb397' 
  AND token = 'TlxzG/pAZ07yYNOnLi9xwyGkfjJTIRvse65VYGnQEzQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00061

JSON explain

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