SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '62e10bb89e659278bfc931091e545b01997aa6a73a17cd9eaab97fd23f19b78a' 
  AND token = 'kb8fYWi5E0gMLL4Xp5sbRPgXw/Sjv/4U6b/UiXaBhEQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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