SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a1dfcaeb1a4972c96f021b2f924dda707f03ea8b05c762d3ade897cde5b8e763' 
  AND token = 'sluBy6BTnEzV1p+rTRpYrx3C069VOJdB+BphgEBWvvo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}