SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'fbc7648b6f5e1672bfa714edb30ad3b25e420996c85c9b9f3cf0147c8d6b6194' 
  AND token = '41WK4QuKjS1c79Ug+jy6er42zNYgM4lROLVNaix//us=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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