SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '96deca285950793637dda16781defa64d66b2a0b1689ec0a04aed4fa745f3fd4' 
  AND token = 'wqjNBJ/mg15XHnhTczXF0PXgdtEPbONGvhugZX4IOho=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}