SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fcfc7a8e724db3c6ca4e545d3989097744c5aa8e337cbfc5c47daf7c343bb1f6' 
  AND token = '7FOMiAPilL9APnUXGfyoYSarc4eSqXRJ0EKMh0HNuN4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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