SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4d2898220d9bdf699c4782c4336c83d12bd386fe444241a48223c9cb0193f834' 
  AND token = 'G6hbCZ2L+5IjdNkqvXio3Yrm4MLuNLFeIDUjS5VcNBw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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