SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'ce84f3f0b3282439c2996888aedd50c6848d82a5aa20659a802cda662e81c0e3' 
  AND token = 'bp7/G0kIaOKGFvYZz/GXnPo4IhqXBMLhr8VwU9Tcznk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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