SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0e74dd42be099032309a7fbcaaeb3179d050c745dc508aa4dca0150b7934ba84' 
  AND token = 'Lat4TsoYEm26RU6Oqga34S6I1YOa3fJuKTpfkaQbry4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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