SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fe8f9d859149240219df45e5f2d421da73f86e11efe2a36d57102c613066d25e' 
  AND token = 'XA5VcE2vOZGvI0i/4EQedWucPuj9eCD5qruf8nPIgEE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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