SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'da70ad74db73eaf4dff1dcb87e78e871d0a35362f82e57b2fbd5d1cbcd949104' 
  AND token = 'nCehOgnv5UvAYZmGB4wJMJXFDlcH4i7v9RTvAbn4WZ0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00011

JSON explain

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