SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7f9532a122ce9ca2c9fe45d253ff5f139d9c68a6d07a9d7d0cf45536c6b85bc4' 
  AND token = 'NeHlCUsxzKwKxZPh5oMcW/Lqud1Lsw3fnFQgm1f8tBA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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