SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5149f7270889c97c64db298fc6a07b577cab42aba3c0e0bc73b3d19c7057e695' 
  AND token = '9wPpjCTfiXVMfhBDRn2CYtvcgtGTo17wvU8qXZ3C6nU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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