SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1a13bc3c89067ae308202f9f0fe201da04dcb621b2a855fa8b7edb7860d2c140' 
  AND token = 'UFthmA5ybjB+UNQE8Ok9FGMDp3QdzS2QgTIDNVYwQQc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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