SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4d198ee118cece56615efdc81b580f0c84c1203fb0ef3e6e1a0f68dc920c2107' 
  AND token = 'F814W6lbXQY+xdqYcNZOVf8BMftHOZSo+w6s62pB4zo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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