SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '58afa6b3fc313899b9d8581626b719df04943f25f8be78473312bd26e369e1d4' 
  AND token = 'a0LUB37JUVaZDnPwxxpeYqx2SJnCA6ItWbYSxGFCmB8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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