SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4e151fbff541489398614dd7bc3ef083aa52ccd33c25a5955ef1fee280e5811d' 
  AND token = 'jVH7q9+mLDVZjGGSPjRNP9XZGbPOQYwvE7N/SHYQKnE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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