SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5380166c853fce679f72143e27d534b42cea3c3ab952ecdc833314c19fe49422' 
  AND token = 'V6Q16nEKNUELqffx7Km6ez5kuRYDO6ZDAwt2BMqxcL4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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