SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '0ff3337688befa70977231f81ffc9eca4cbd983b0e7b96ac3400d5a11089eb52' 
  AND token = 'YYHxLxEYcJJqcbtOiwXueKSvXFH96L3DMxKphofLP58=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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