SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1dd76c563de3545e106c1c92812f30ded33bbb31304e59316c106141dff2130a' 
  AND token = 'VCmmR8lsMlJAo2mngqsUvzdMXFJ2k59+ouO+iFPHg1Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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