SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '70c8bf5bc5f8ce6dd568903354d94211fb106221aa5b56ac206a6eaaa422586d' 
  AND token = 'JnXBENmj3Pvb90Jkl+u+O4FDjIFzTjQAbVqVYQkFDCc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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