SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'fc2fb0e6897f4d93dfcc7e8a12c115faf2068be21a7bf7bc2ac09edaccc58a79' 
  AND token = 'H6h0zRJZCvq+LBym/5QipmpSZbxwG7VpxFhDqv/3fo0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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