SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e4c6636042408286de639d847d37336d674bf9307f4d62e0ba064cd4b07cb69b' 
  AND token = 'welZFXMP5mgGo9dAAVMjCqhwC5cx73eKKZjauf/9x4k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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