SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'af80da66f420478b32158d8b5d7a2aa4d2512b92fc5b3be6ab3ce5be0dcf1b87' 
  AND token = 'Iok0b+2dCwjxMO/GsNFhlbG3NQHVfEO4Djo4AJJtD44=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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