SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '955fe036d0b5a376162d5186a9187704e362634bd62c45229b42c39f334317a5' 
  AND token = 'aW48dWz4zW6s3NdeuMolNFNvlIYFRWSKkLu2ItdFtHw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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