SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ae3a93ab363f859a7e62911bd6e89dca1c67207d086738685c57280c8f4b51b8' 
  AND token = 'i22QQXMIe6yrXK3ql7vdVHlxz8c9PJwwm1S1admRLm4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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