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SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '6166e804a753c2fe5e8a2d603ef8030f2f1bd57d5b5e4bef3690923b2eddbb37' 
  AND token = 'A0m8bwXcavzrAk3cmwyQxq2ywsJZV5RGx3vaS+oLOpI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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