SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '539dda4facdb147787a33b3e1c79eec0e15c906391a09204db6e881b3a39f20b' 
  AND token = 'Qt89lw2M+jnhmQYYuda9AjbgC/uSMPPTExa9bIJEaK8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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