SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'c26081a1c4b220ef6c90cd979f6c32155fdfc807ff7114e017a817d4a05e3e51' 
  AND token = 'l7Ma275DFw2fDi3fOS0iOvfTn/tzB+WlYwO6TlDaf9Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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