SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ea051ae8edb06972efe477356297e5d44d0e66329762626146f659ea6b09457d' 
  AND token = 'qWSBXqAaRknBYLkRGJXkFtR3989eSoIEi+/OVX3GYP0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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