SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'be4a213c5a5f36212fb0843b0e93916a80a50468b07b24597fed6d0aa1f03aa1' 
  AND token = 'fmKwNANXfmW6N0JicSuyLpXeMQ+vEIf+pdlEn7MYAao=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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