SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b93e6f536bdab2eb2571599ae2e81d7c505eeb420503b9359d4b9c6ac627956a' 
  AND token = 'JT9F+Ex03wHq6aa3mZ23HyT0m48gWpPolNRTKhwBmVI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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