SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'c8808558dad7e2a471d30be32499b6b28219d997f6b01dcf945575e5021ffb55' 
  AND token = 'f+yWuV/zlRHnq5Qe4I38H58UCulBW0fthA99JPr+E6s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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