SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'df2ba8f71a134252786a3066fc021894ba27a2c66a1ea837c148bcb386097df1' 
  AND token = 'IdIRRKRNH1CuPywoveBdJjFZgTBIJEPJqaZx2QhsXOY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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