SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b661c6ee9e56a904ddc4449a2fe229fec70da705d49b83a10e018a7f31233839' 
  AND token = 'y8GEDE6WBP/1JnTjh1oEe8PgdgYjiApHE8xNCbs5aqs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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