SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '13641fe2d9660897097bc9e3da154815b899fad1061e613634ce7322254f3688' 
  AND token = 'CxtHAIZev38oOLjWjsQ22h88jPwjKLCNtfPiYbyJv8Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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