SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '306a3b06114b6df03cc69ae4e133f77272b4ce7a5d575fb62a7b5e158d0b421b' 
  AND token = 'Mwi9S30g3TBZNl+L4SUbvlYXA+YoxJRCdf5vpwttscQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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