SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '5897c71ec21b04136ef9307914c5c0c891890e14d9b0f085e5bc625b1aff9a69' 
  AND token = '7RcyfXV6afXyxjksX0EdvpwVVudPZD4PFSie70nMXKw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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