SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '318d19783f96eb55d170196772f0c6617da0129f76ded0cd78d3b2488fbf98d9' 
  AND token = 'U4MgtHYAPrwvJK3+FQ248/Z4twI39vvpCoSnlHDhey4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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