SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b7f14c1b4cb88675704786f538615ff22b281e01853f8ad2b2759b3bd663cefd' 
  AND token = 'eMkCKCHYJTvlPANXBebmIVmAGp7EyNu7FJaRugVTFK8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}