SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '335e7695b09fa5a765e282da898d7d3b3f69a56d60de55d120ac0a92fded8e4f' 
  AND token = 'fvt75fVutMODHqVJLBQmPogdKNEwNP2Lb/mn+ynUD+4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00050

JSON explain

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