SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '55d9b9970fe796e037dded800b6dc1f3b45519f1f9b51a00ae04bff47b796f3a' 
  AND token = 'tovfPq3sjQERc+isdIERUTKbXeQ0vV74I5WUNyKtkH0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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