SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e83ddd791571e9569233528f3c8fa4f7b46b4767d541dd74e0904c1ee280f6fd' 
  AND token = 'ryC7AnLW2eVpPu5FjFLB5G/Gz87x58TRgAjvMHoHEqw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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