SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '97ffb521f2206ddc2572169f949155b91abf7f34ba21948810a79f0f523b0138' 
  AND token = '+S1+ovrg4TBcDADq2RL1/IGF7KuVTGzv6uCWwcegTVI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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