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SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'd3ee756f219459b0278e7e2add2fa43ceb8f7855ddc2a64b452869a5a9eb3b7e' 
  AND token = 'jCsPyS+r5kEDNVxdEro8lgFHv8hJ19zAeVSnBI83r/M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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